四川省山洪灾害风险评估与区划

基于GIS技术以及全国山洪灾害防治规划资料,以四川省为例,借鉴自然灾害风险概念,对山洪灾害危险度、易损度和风险度进行了量化与分析,并根据区划理论的一般原则和全国山洪灾害一、二级防治分区范围,对四川省山洪灾害风险进行了区划。结果表明:四川省山洪灾害可划分为6个风险区划单元,5个风险等级(低风险区、较低风险区、中风险区、较高风险区、高风险区),各风险等级所占全省面积的比例分别为59.9%,12.8%,14.9%,5.9%和6.5%。其中,四川盆地及周边地区山洪灾害风险水平较高,中风险区等级以上的面积占到了四川盆地及周边总面积的近80%;其次,秦巴山地区为山洪灾害次严重地区,中风险区等级以上的面积占到了区域总面积的近18%;其它几个三级区域山洪灾害风险水平不高,大多处于低风险和较低风险水平。

Risk Assessment and Regionalization of Mountain Torrent Disaster in Sichuan Province

Based on GIS technology and the national planning data about prevention of mountain torrent disaster , the risk of mountain torrent disaster,vulnerability and risk degree of Sichuan province were quantified and analyzed in this paper by using the concept of natural disaster risk .According to the general principles of the regionalization theory and the regionalization classification of national mountain torrent disasters,the risk regionalization of Sichuan province was put forward.Results show that the risk levels of mountain torrent disaster in Sichuan province can be divided into 5 kinds:low risk,low-middle risk,middle risk,middle-high risk,and high risk.The percentage of area of the five risk levels accounting for total area of the province is 59.9%,12.8%,14.9%,5.9% and 6.5%, respectively.In the Sichuan basin and the surrounding regions,risk level of mountain torrent disaster is high,for area with the risk level middle or above takes up nearly 80% of total area of these regions .Furthermore,mountain torrent disaster in mountain regions of Qinling and Dabashan is relatively serious,for the risk level is middle or a-bove in nearly 18% of total area of the mountain regions.Finally,risk levels of mountain torrent disaster in several other regions is not high,most of them are low risk and low-middle risk.